GABAergic control of hypothalamic melanin-concentrating hormone-containing neurons across the sleep-waking cycle

Romain Goutagny (1) , Pierre-Hervé Luppi (2) , Denise Salvert (2) , Damien Gervasoni (3) , Patrice Fort (4)

1 LNCA - Laboratoire de neurosciences cognitives et adaptatives
2 Physio-pathologie des réseaux neuronaux du cycle veille-sommeil
3 CRNL - Centre de recherche en neurosciences de Lyon - Lyon Neuroscience Research Center
4 Trelleborg

The perifornical-lateral hypothalamic area is implicated in regulating waking and paradoxical sleep. The blockade of GABAA receptors by iontophoretic applications of bicuculline (or gabazine) into the perifornical-lateral hypothalamic area induced a continuous quiet waking state associated to a robust muscle tone in head-restrained rats. During the effects, sleep was totally suppressed. In rats killed at the end of a 90 min ejection of bicuculline, Fos expression was induced in approximately 28% of the neurons immunoreactive for hypocretin and in approximately 3% of the neurons immunostained for melanin-concentrating hormone within the ejection site. These results suggest that neurons containing melanin-concentrating hormone are not active during waking and that the lack of a potent GABAergic influence during waking is consistent with their role in sleep regulation.

Domaines: Neurobiologie

Romain Goutagny, Pierre-Hervé Luppi, Denise Salvert, Damien Gervasoni, Patrice Fort. GABAergic control of hypothalamic melanin-concentrating hormone-containing neurons across the sleep-waking cycle. NeuroReport, 2005, 16 (10), pp.1069-1073. ⟨10.1097/00001756-200507130-00008⟩. ⟨hal-02265100⟩